Adherence: The Furnace Filter Analogy

Jeannette Yeznach Wick, RPh, MBA, FASCP

Published Online: Thursday, February 1, 2007

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If you ask furnace repairmen to
describe the greatest frustration of
the trade, you will hear a familiar
story. Even though the repairmen
remind people and offer ways for them
to remember, most people fail to clean
or replace their furnace filters monthly.
If people do remember, they may not
do the job correctly or well. That problem
sounds similar to a problem that
health care providers face every day:
medication and treatment adherence.
Consider these facts:

More than 29% of adults have hypertension
(HTN)1,2 and are at increased
risk for adverse outcomes. Although
effective treatment reduces risk,3,4
most patients with HTN have poorly
controlled blood pressure,5,6 and up to
70% of patients are nonadherent with
prescription medication.1,7-9

Among diabetics treated with sulfonylureas,
adherence is estimated to
be as low as 10% to 50%.10

Among HIV-infected people, high-level
adherence (in the range of 90% to
95% of doses taken correctly) is necessary
to prevent viral resistance and to
improve immunologic, virologic, and
clinical outcomes. Regardless, adherence
often is reported to be less than
70%.11

Most pharmacists know some of the
factors that increase the risk of nonadherence:

Increasing numbers of drugs and
doses

Difficult administration routes or
timing

Silent or symptomless diseases

Cost of medications

Intolerable side effects

In the past, health care clinicians
have used patient self-report, clinician
impression, pill counts, pharmacologic
tracers, and electronic measurement
devices to assess adherence. Examination
of pharmacy claims data is a
recent method that allows access to
aggregate data on medication dosing
and refill patterns. The new buzzword
is medication possession ratio
(MPR),12,13 which now is used frequently
as an adherence measure.10,12-25 (see
sidebar).

Poor medication adherence is different
from poor furnace filter maintenance
in that furnace repairmen do not
have aggregated statistics about nonadherence
as pharmacists do. Ultimately,
statistics do not create change
in and of themselves, and direct-care
clinicians have to intervene. Medication
adherence and furnace filter
maintenance are similar in that access
and cost can be barriers, and cultural
beliefs or misinformation also may be
important.

Hypertensive patients, for example,
often indicate that they become nonadherent
because they believe that
they are cured (46%), or they perceive
that their prescribing clinician directed
them to stop (25%).26 Patients may forget
to take medications, misunderstand
when or how to take them, take
extra doses to treat stubborn symptoms,
or consciously decide to stop
taking medications.27 Clinicians may be
ignorant of these problems and may
interpret unidentified nonadherence as
poor drug effectiveness.

Communication technique is key to
improving adherence, especially communication
that employs a patient-centered
approach that allows patients
to participate in shared decision making.28-31 Unfortunately, physicians rarely
engage patients in decision making:
often they just inform patients of the
need for medication.30 They also are
unlikely to question patients about
medication-taking behaviors.32

Changing Behavior

Clinicians cannot expect to change
patient behaviors without first knowing
current medication-taking behaviors.
Asking questions is the cornerstone of
the approach, and most communication
experts recommend using direct
and information-intensive approaches
to assessing adherence.33 Despite decades of education directed at health
care providers to improve communication,
providers frequently use inappropriate
structure, temporality, content,
and style when asking patients about
adherence.34

The structure of a question either
promotes or inhibits the amount and
kind of information sharing from
patients. Patients will respond to
closed-ended questions with a simple
yes or no, rarely venturing any additional
information. Declarative questions
(eg, "You take your medication,
right?") also squelch patients' propensity
to volunteer extensive information.
Patients are not being intentionally dishonest;
instead they engage in the
human tendency to be agreeable. (My
last furnace repairperson used to say,
"You change your filter monthly, right?"
Of course, I agreed.)

Switching to a subtly interrogative,
open-ended question approach that
uses question strings allows collaboration
and also permits patients to verbalize
concerns and beliefs. Pharmacists
can say, "Tell me how you take
this prescription," and then help the
patient see how to improve. The result
should improve adherence.34

Providers also need to simplify their
communication. Asking about medications
by pharmaceutical or trade
names can confuse some patients.
Describing tablet or capsule color and
size can prompt better responses,
especially for patients with low health
literacy.35,36 Confrontational communication
styles will tend to make patients
defensive and will erode potential
provider-patient therapeutic alliances
(eg, "Didn't I tell you to take it in the
morning on an empty stomach?").37,38
Providers who insist on communication
that transfers information to the
patient rather than exchanges information
collaboratively miss an opportunity
to improve adherence.39-41

In addition to communication barriers,
patients' beliefs about medication also
may contribute to problems with communicating
about medication taking.42
Demographics such as age, gender, race,
intelligence, level of education, marital
status, and social status generally do not
contribute to or affect adherence. Elders'
adherence problems usually are
related more closely to the medication
regimen's characteristics than to age
itself. Limited access to health care,
financial problems, and lack of social
support can undermine adherence.43

End Note

My furnace repairperson cajoled me
into being more adherent to my furnace
maintenance schedule. He pointed
out barriers (poor location, dirty
job); factors that increased my risk of
poor outcome (multiple animals in the
house); and the inevitable outcome if I
failed to adhere (costly furnace
repairs). He taught me ways to remember
(put a note in with my bills payable,
ask for help from family members).
Then, he stuck out his hand to shake
and said, "Promise you'll do better." We
established an informal "contract," and
my adherence is better.

Try a similar approach when you
counsel patients about improving
adherence, but realize that the patients
with whom you can expect to see the
best return on investment are those
that are mildly to moderately nonadherent.
Do not expect to change
patients who are completely nonadherent
into adherence stars. Nevertheless,
do not let a counseling opportunity
pass you by. It may very well be
the one that may promote some positive
change.

Ms. Wick is a senior clinical researchpharmacist at the National CancerInstitute, National Institutes ofHealth, Bethesda, Md. The viewsexpressed are those of the authorand not those of any governmentagency.

References

1. Hajjar I, Kotchen TA. Trends in prevalence, awareness, treatment, and control of hypertension in the United States, 1988-2000.
JAMA. 2003;290:199-206.

3. Amery A, Birkenhager W, Brixko P, et al. Mortality and morbidity results from the European Working Party on High Blood Pressure in the
Elderly trial. Lancet. 1985;1:1349-1354.

4. Prevention of stroke by antihypertensive drug treatment in older persons with isolated systolic hypertension: final results of the
Systolic Hypertension in the Elderly Program (SHEP). JAMA. 1991;265:3255-3264.